Save Our Sleep by Tizzie

Clare • Chloe born 7/2/17
Just wondering what your opinion / experience with Save Our Sleep by Tizzie is. Just came across the app (which is meant to be used in conjunction with her book) and the suggested routine is breastfeeding every 4 hours! My girl feeds approx every 2 hours.. 
My 14 nearly 15 week old used to sleep from 7.30pm to 6.30am with two feeds during the night (at approx 12.30am and 4.30am). She has now decided she wants to wake up nearly every 3 hours so I'm trying to find some good info about sleep and self settling.